Heat exchanger



y 1952 u. LARKIN 2,595,472

HEAT EXCHANGER Filed May 5, 1949 Patented May 6, 1952 UNITED STATESPATENT OFFICE 2,595,472 HEAT EXCHANGER Lester U. Larkin, Harvey, 111.,assignor to Lincoln M. Larkin, Libertyville, Ill.

Application May 3, 1949, Serial No. 91,070

4 Claims. 1

This invention relates to heat exchangers in general and includes allsuch evaporators, condensers and other similar apparatus and equipmentwhich employ a conduit for fluid, this fluid either absorbing oremitting heat during operation of the equipment. More specifically, theinvention relates to a conduit of a particular type and formation whichis adapted to be wound about a container such as an evaporator wherebyone side of the container or evaporator acts as a closure part'for theconduit.

An important object of the present invention is the provision of a heatexchanger employing a new and novel conduit formed of an element whichis relatively semi-circular or hat-shaped in cross section,this elementhaving outwardly extending relatively short attaching legs adapted to besecured to the surface of a container or other structure such as acondenser, the said element being corrugated at its crown to providealternate ridges and furrows to effect greater efficiency of the fluidwhich passes through the conduit.

Another object of the invention resides in the formation of a flexibleelement in strip form which has an outwardly extending body withrelatively short attaching legs for the attachment of the element to asurface of a body such as an evaporator, the strip body at the crown orapex thereof being corrugated in the form of alternate ridges andfurrows so as toeffect greater elliciency of the fluid which passesthrough the conduit when the strip is secured to a body such as anevaporator.

Numerous other objects and advantages will be apparent throughout theprogress of the specification which follows.

Referring to the drawings:

Fig. 1 is a detail perspective view of one form of heat exchanger orevaporator embodying the invention;

Fig. 2 is a detail transverse sectional view on the line 2-2 of Fig. 1;

Fig. 3 is a detail vertical sectional view on the line 33 of Fig. 1;

Fig. 4 is a detail longitudinal sectional view on the line 4--4 of Fig.3;

Fig. 5 is a detail side elevational view of the improved strip which isemployed for forming the conduit; and

Fig. 6 is a detail perspective view of the improved strip.

The particular construction herein shown for the purpose of illustratingthe invention comprises an elongated strip I of metal or other suitablematerial, this strip being provided with an outer dome-shaped part 2which is relatively semi-circular in cross section. The dome-shaped part2 terminates in outer legs or flanges 3 and 4 which are adapted to besecured to the body 5 of certain refrigerator equipment such as anevaporator. When the legs or flanges 3 and 4 are secured to the body 5,a hollow tubular conduits is provided by a part of the body and thedomeshaped part 2 of the strip I. The hat-shaped strip I is adapted tobe wound spirally about the body 5 and terminates at its upper end in aninlet I and at its lower end in an outlet 8.

The strip I i secured to the body 5 by seam welding the legs 3 and 4directly to the body whereby the conduit 6 is formed for receivingliquid which flows in the inlet I and out of the outlet 8. The bulged ordome-shaped part 2 of the strip is preferably formed with corrugations 9comprising alternate ridges Ill and furrows II whereby a turbulence isprovided as the fluid is passing through the conduit. The turbulencethus created provides for increased efficiency of the refrigerant andprovides for greater coverage of the refrigerant because the refrigerantis directed against the walls of the conduit including particularly theenclosing .walls of the body 5. The greater turbulence of the fluidpassing through the conduit also tends to wipe off any oil which mayengage the surfaces of the strip or the body and therefore provide forgreater heat exchange capabilities.

The strip is adapted to be rolled in the configuration shown sectionallyin Fig. 3 and thenprovided with the corrugations at the crown, or thecorrugations may be formed in the crown while the strip is being formedduring the rolling operation.

It is desirable that the material from which the strip is made becontinuous and of "sheet metal preferably not greater than 25- gaugethickness. However, on larger devices a heavier gauge material may beused, excellent results having been obtained from rolling the strip of22-gauge sheet metal so that the dome-shaped part at its greatestdimension will be about 1 3'. The overall width of the strip ispreferably 1%" for a conduit of the size indicated. The legs 3 and 4 mayeach be A" wide, the width of the dome-shape part between the legs being7 However, the various dimensions of the strip may be varied as desired,depending upon the type, kind and size of structure for which thematerial is to be used.

The strip is adapted to be applied to the walls of the body 5 so thatthe walls will act as one side of the conduit, the other side beingclosed by the dome-shaped part 2 and the legs 3 and 4 as clearly shownin Fig. 3. The legs 3 and 4 are seam welded to the body 5 as indicatedat 12 and I3, respectively.

In Fig. 1 the strip of conduit material is shown as starting at an uppercorner of the body 5 at the inlet 1 and then winding helicallyabout thewalls toprovide the surrounding fluid conduit. The helical passage issuch that fluid within the conduit will flow by gravity from the inlet 1to the outlet 8, whereupon all danger of oil being dripped within theline is definitely overcome. The corrugations 9 which form the alternateridges and furrows l and II, respectively, cause a turbulence of thefluid as it passes through the conduit and create greater efficiencybycausing the fluid to definitely contact the walls of the container aswell as wiping off any oil which may appear at the inner surfaces. Thecorrugations 9 also permit the strip I to be bent or flexed more easilyaround the corners of the body 5, thereby preventing excessive internalstrains from developing in the strip at the points where the strip is sobent.

The strip of material preferably is applied by a continuous seam weldingoperation in the manner' disclosed in application Serial No. 546,827,filed July 27, 1944 now abandoned. The manner in which the material isspirally wound about the body consists in rotating the body 5 whileraising or lowering the body during the time the material is applied tothe body. One means of scam welding the strip material continuouslyabout the body in helical form is disclosed in applicants co-pendingapplication Serial No. 130,- 036, flled November 29, 1949.

The invention provides an extremely inexpensive evaporator or otherdevice by winding about the walls thereof a strip of preformed materialhaving a dome-shaped part with legs or flanges for attaching the striptothe body. The domeshaped part of the strip is provided with corrugationsby means of alternate ridges and furrows so as. to create turbulence ofthe refrigerant as it flows in a spiral path about the container. Theconduit material herein described is for the purpose of receiving fluid,and the term fluid is used herein in its broadest sense and includesboth liquids and gases.

The strip forming the conduit is capable of being quickly andeconomically manufactured and quickly and economically attached to itscooperating container or structure.

The strip is applied so that the opposite walls of the structure will,be left smooth and clean and therefore will be capable of being enameledif desired.

Changes may be made in the form, construction and arrangement of theparts without departing from the spirit of the invention or sacriflcingany of its advantages, and the right is hereby reserved to make all suchchanges as fall clearly within the scope of the following claims.

The invention is hereby claimed as follows:

1. A heat exchanger comprising a sheet metal panel, a sheet metal striphaving side walls and an integral top wall disposed upon and secured tosaid panel to form a fluid passage between said panel and said strip,the edges of the side walls of said strip being sealed directly to thepanel, the top wall of said strip being transversely cor rugatedthroughout the length thereof.

2. A heat exchanger comprising a sheet metal body forming enclosingwalls, a sheet metal strip having side walls and an integral top walldisposed helically upon and secured to said enclosing walls to form afluid passage between said enclosing walls and said strip, the edges ofthe side walls of said strip being sealed directly to the enclosingwalls of the body, the top wall of said strip being formed withtransverse corrugations, to promote turbulence in liquid refrigerantflowing in the passage.

3. A turbulent fluid flow device comprising a sheet metal panel, a stripof sheet metal applied upon the sheet metal panel to form a conduitbetween said strip and panel, the strip comprising a channel-shapedelement having side walls and anintegral top wall, said side wallshaving outstanding flanges adapted to be sealed upon the panel, and thetop wall of the strip being formed with transverse corrugations alongthe strip.

4. A turbulent fluid flow device comprising a sheet metal panel, a sheetmetal strip configurated transversely to provide an elongated channeledelement having side walls and anintegral top wall whereby the marginaledges of the side Walls may be sealed, therealong, to the sheet metalpanel to provide a conduit between the strip and the panel, the top wallbeing alternately ridged and furrowed transversely of the stripsubstantially throughout its entire length to provide successiveconstrictions and enlargements in the conduit for turbulating fluidflowing therethrough.

LESTER U. LARKIN.

REFERENCEfi CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date Re. 18,633 Mufily H Oct. 18, 1932969,018 Willman Aug. 30, 1910 1,906,296 Williams May 2, 1933 2,118,637Atchison May 24, 1938 2,156,544 Raskin May 2, 1939 2,292,803 Steenstr-upAug. 11, 1942 2,371,215 Benson Mar. 13, 1945

